The speed and bandwidth of data transmission over fiber optic cable renders optical fiber communication particularly advantageous for various applications. Optical fiber transmissions typically include an optical transmitter at one end and an optical receiver at the other end. The distance between these devices is limited by the power of the optical transmitters, degradation of the laser diodes, signal loss and dispersion in the optical fiber, and the sensitivity of the optical receiver. Depending on the distance between the desired end points of the optical fiber transmission system, optoelectronic repeaters are usually included for boosting the signal before arriving at the desired end point.
In some systems, communications can be disrupted when the power level used to transmit data is either too high (signal overdriven) for the short distance to the receiver or is too low (signal underdriven) for the extended distance to the receiver. To protect against disruptions in communication, power level monitoring is implemented at the optical transmitter. However, the power level corrections that are made at the optical transmitter are through trial and error because the effect at the optical receiver is not known until after a power level is set. This approach also has the drawback of losing data during active communication. Signal degradation can also occur due to aged laser diodes and adverse changes in ambient temperatures.
Another approach for adjusting the output signal power level is monitoring the power level of the signal at the receiver, which is sometimes referred to as “weak link detection.” Drawbacks to this approach include the need for complex and cumbersome diagnostic equipment, diagnostic optics, diagnostic data, and/or diagnostic software to regularly monitor communications between the transmitter and the receiver and/or the need to monitor the receive power level.
A method and a system that addresses the aforementioned problems, as well as other related problems, are therefore desirable.